Publications by authors named "Karthi Sengodan"

This study explores the larvicidal potential of methanolic flower extracts from Phoenix pusilla (Pp-Fe), its major compound, and malathion (MLT), against laboratory strain (LS) and field strain (FS) of Aedes aegypti, the dengue mosquito vector. We identified thirty-one derivatives, with methyl oleate (MO) comprising 28.5% of Pp-Fe.

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Histone acetylation, a crucial epigenetic modification, is governed by histone acetyltransferases (HATs), that regulate many biological processes. Functions of HATs in insects are not well understood. We identified 27 HATs and determined their functions using RNA interference (RNAi) in the model insect, Tribolium castaneum.

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Green pesticides, derived from natural sources, have gained wider attention as an alternative to synthetic pesticides for managing polyphagous pests, such as Spodoptera litura. In this study, the methanolic flower extract of Nyctanthes arbor-tristis (Mx-Na-t) was subjected to chemical screening, and 3-hydroxy-1,2-dimethyl-4(1H)-pyridone (3H-dp) and tyrosol (Ty-ol) were identified as the major derivatives. The toxic effects of Mx-Na-t (500 ppm) were highest in third-instar S.

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Current vector control strategies based on synthetic chemicals are not eco-friendly against non-target organisms; hence, alternative approaches are highly required. Commercially purchased oil of Mentha spicata (Spearmint) and Eucalyptus citriodora (Citriodora) were examined against the medical pest Cx. quinquefasciatus (Say) and their non-toxicity on the aquatic species was evaluated.

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Article Synopsis
  • The study focuses on assessing the toxicity of compounds derived from the green seaweed Chaetomorpha antennina, which is being explored as a sustainable pesticide against the pest Spodoptera litura.
  • Ecotoxicological laboratory assays were conducted to measure the effects of these seaweed compounds on the earthworm Eudrilus eugeniae, evaluating changes in morphology, physiology, and biochemistry.
  • The assessment includes analysis of enzyme activities (like acetylcholinesterase, catalase, and superoxide dismutase) and gut histology to ensure the safety of the compounds for soil organisms.
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Article Synopsis
  • * Combining the methanol extract with the biocontrol agent Trichoderma viride resulted in significant antifungal activity (82.92%) and reduced disease incidence in tomato plants affected by Fusarium wilt.
  • * The research also highlighted that the combined treatment led to higher levels of defense enzymes in the plants, suggesting that their increased presence plays a critical role in enhancing disease resistance.
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The active and inexpensive catalyst cupric oxide (CuO) loaded foliar fertilizer of graphitic carbon nitride (-CN) is investigated for biological applications due to its low cost and easy synthesis. The synthesized CuO NPs, bulk g-CN, exfoliated -CN, and different weight percentages of 30 wt%, 40 wt%, 50 wt%, 60 wt%, and 70 wt% CuO-loaded -CN are characterized using different analytical techniques, including powder X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis, and ultraviolet-visible spectroscopy. The nanocomposite of CuO NPs loaded -CN exhibits antibacterial activity against Gram-positive bacteria ( and ) and Gram-negative bacteria ( and ).

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Mosquitoes are the potential vectors of several viral diseases such as filariasis, malaria, dengue, yellow fever, Zika fever and encephalitis in humans as well as other species. Dengue, the most common mosquito-borne disease in humans caused by the dengue virus is transmitted by the vector . Fever, chills, nausea and neurological disorders are the frequent symptoms of Zika and dengue.

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More recently, the number of studies on the impacts of microplastics (MPs) on plants has drawn attention considerably. However, many of these studies focused on terrestrial plants, with vascular plants from freshwater ecosystems being little studied. Thus, we aimed to evaluate the possible effects of exposure of Salvinia auriculata, for 28 days, to different concentrations of polyethylene MPs (PE MPs - diameter: 35.

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(Fabricius) is an agriculturally significant polyphagous insect pest that has evolved a high level of resistance to conventional insecticides. A dietary assay was used in this work to assess the resilience of field populations of to λ-cyhalothrin. Analysis of the function and expression of the cytochrome P450 gene was used to test the sensitivity of larvae to sub-lethal concentrations of the insecticidal plant chemical Precocene 1, both by itself and in combination with λ-cyhalothrin.

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Green synthesis of silver nanoparticles (AgNPs) has gained greater interest among chemists and researchers in this current scenario. The present research investigates the larvicidal and anti-proliferation activity of AgNPs derived from aqueous leaf extract (-ALE) as a potential capping and reducing candidate. The synthesized AgNPs were characterized through-UV-spectra absorption peak at 425 nm.

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Article Synopsis
  • The study investigates the use of Desmostachya bipinnata for creating titanium oxide nanoparticles (TiONPs) as eco-friendly alternatives to traditional insecticides, focusing on their effectiveness against mosquito (Aedes aegypti) and agricultural pest (Spodoptera litura) larvae.
  • The biosynthesized TiONPs were characterized using various analytical techniques and demonstrated high larvicidal activity, with up to 96% mortality at a concentration of 900 μg/mL for the targeted pests.
  • In contrast to synthetic pesticides, TiONPs showed lower toxicity to non-target organisms, indicating their potential as safer pest control agents.
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The use of vegetal species for gold nanoparticles (AuNPs) biosynthesis can constitute an alternative to replacing the extensive use of several hazardous chemicals commonly used during NPs synthesis and, therefore, can reduce biological impacts induced by the release of these products into the natural environment. However, the "green nanoparticles" and/or "eco-friendly nanoparticles" label does not ensure that biosynthesized NPs are harmless to non-target organisms. Thus, we aimed to synthesize AuNPs from seaweed Gracilaria crassa aqueous extract through an eco-friendly, fast, one-pot synthetic route.

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The success of long-lasting insecticidal nets (LLIN) as the primary method for preventing malaria is threatened by pyrethroid resistance in vectors. New generation long-lasting nets incorporating PBO synergist (piperonyl butoxide) with pyrethroid are designed to control insecticide-resistant mosquitoes. The efficacy of Veeralin® PBO LLINs was evaluated in experimental huts against wild free-flying pyrethroid-resistant ().

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Insecticides are widely used in agriculture as effective means to control pests. However, pests have not been completely mitigated with the increased use of insecticides. Instead, many side effects have arisen, especially the '3Rs' (resistance, resurgence, and residue).

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The identification of SARS-CoV-2 particles in wastewater and freshwater ecosystems has raised concerns about its possible impacts on non-target aquatic organisms. In this particular, our knowledge of such impacts is still limited, and little attention has been given to this issue. Hence, in our study, we aimed to evaluate the possible induction of mutagenic (via micronucleus test) and genotoxic (via single cell gel electrophoresis assay, comet assay) effects in Poecilia reticulata adults exposed to fragments of the Spike protein of the new coronavirus at the level of 40 μg/L, denominated PSPD-2002.

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A field survey was done in teak ( F.) forests in South India to explore the entomopathogenic effect of (Ascomycota: Sordariomycetes) against teak defoliator, (Lepidoptera: Hyblaeidae). About 300 soils and infected insect samples were collected during the survey and thirty-six fungal isolates were isolated from soil and insect samples and characterized.

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The South American pinworm (Meyrick) (Family: Gelechiidae) is one of the most devastating lepidopteran pests in the developing countries of South America, Africa, and Asia. This pest is classified as the most serious threat for tomato production worldwide. In the present study, we analyzed RNAi-mediated control through exogenously applied dsRNA delivery on tomato.

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The sustainability of agroecosystems are maintained with agro-chemicals. However, after more than 80 years of intensive use, many pests and pathogens have developed resistance to the currently used chemistries. Thus, we explored the isolation and bioactivity of a chemical compound, Precocene I, isolated from the perennial grass, (L.

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Reduced pathogen resistance and management of the left-over rice stubble are among the most important challenges faced in rice cultivation. A novel and eco-friendly strategy to synthesise 'Fungal Chitosan' (FC) from Aspergillus niger using rice straw could serve as a sustainable treatment approach to improve both disease resistance and yields, while also effectively managing the rice stubble waste. The FC treatment promoted germination as well as growth parameters in rice varieties, TN1 (high yielding-susceptible) and PTB33 (low yielding-resistant) better than a commercial chitosan (PC).

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Fab. is a polyphagous pest causing damage to many agriculture crops leading to yield loss. Recurrent usage of synthetic pesticides to control this pest has resulted in resistance development.

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Aegle marmelos (L.) Correa belongs to the family Rutaceae is generally known as "bael fruit tree" occuring across the south Asian countries. The current investigation screened the main derivatives from crude ethanolic extracts of the Bael tree leaf and evaluated activity effects on the larvae and adults of Aedes aegypti (L.

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Article Synopsis
  • * GC-MS analysis identified nine major compounds, with HDa showing the highest peak area percentage (14.63%), and indicated that these extracts and their derivatives had significant larvicidal effects that varied with dosage and larval stage.
  • * Sublethal doses of the extracts affected larval development, adult lifespan, and enzyme activity, resulting in notable morphological changes in gut tissues, highlighting their potential as effective pest management agents in agriculture and public health.
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The petroleum ether crude extracts of A. conyzoides (Pe-Ac) were used to treat three medically intimidating pests of Aedes aegypti, Anopheles stephensi, and Culex quinquefasciatus, to evaluate their non-target screening against the mosquito predator. The chemical scanning of Pe-Ac through GC-MS analysis revealed a total of nine compounds and the maximum peak area was observed in 1,5-Heptadien-3-yne (22.

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